The objective of this proposal is to test the hypothesis that altered activities of certain glycosyltransferases in respiratory epithelium are responsible for longer carbohydrate chains and higher sulfate content of mucous glycoproteins secreted by respiratory epithelium in cystic fibrosis patients. Sucrose homogenates of tracheobronchial and nasal epithelium from patients with cystic fibrosis, chronic bronchitis, other hypersecretory states and from individuals with no known respiratory tract disease (normal) will serve as sources of glycosyltransferases. Molecules with well-defined structure will be used as the glycosyltransferase acceptors for the radioactively labeled sugars from sugar nucleotide substrates. The reaction product of each glycosyltransferase will be characterized with respect to the identity of the transferred sugar, site and linkage of the transferred sugar, and anomeric configuration of the newly synthesized glycosidic bond. These studies will provide information concerning regulation of oligosaccharide chain synthesis for human respiratory mucous glycoproteins.